Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
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will (hopefully) never comingle. These fluids include the engine oil, which only has to be con- cerned with the engine, an ATF or manual transmission fluid (or perhaps no fluid if a dry manual tranny) for the transmission and then gear oil for the rear end. "A motorcycle engine oil used in common-sump architectures must do the duties of all these flu- ids at once, simultaneously meet- ing the performance demands of the engine, clutch and gearbox. This is a lot to ask of a single fluid, especially since the total quantity of engine oil available to lubricate these components is severely limited by space. Add in the fact that many of the performance requirements of the individual components are at odds with one another and you're left with a unique and challenging problem that requires a tailor- made fluid to meet each require- ment as optimally as possible, while minimizing any detriment to the aforementioned opposing demands." Riley echoed this with a few other important points. "Pas- senger car motor oil (PCMO) and motorcycle oil are similar from a base oil standpoint but very different when it comes to additives. PCMO is not formu- lated for use in vehicles with a 'wet' clutch, found in nearly every motorcycle engine. Motorcycle oils utilize 'friction additives' to en- able the motorcycle's metal and fiber clutch discs to 'grip' each other, allowing for the controlled transfer of power from crank to transmission. Look for oils with true JASO certifications. Without 'friction additives' a motorcycle's wet clutch will not 'lock up' and will con- tinuously slip under load." To finish off this point about using the proper oil for the application, Mar- cella pointed out that, "I work for Maxima and I don't use Maxima in any of our cars. I use the oils that the manufac- turer recommends." A high-end motorcycle racing oil is not going to be better for your car and the opposite is true. How about Shell Rotella, this seems to be a popular choice for four-stroke motorcycles, and it is less expensive than most motorcycle oils. If you search online discus- sions regarding motorcycle oils, you will likely find a lot of people recommending Shell Rotella. This is a product that was designed for diesel truck and automotive engines, which create a lot of soot and contaminants in the oil. Diesel engines typically have long intervals between oil changes as well, so Rotella includes a lot of detergents and additives to com- bat these issues that are specific to that type of engine. Those properties may be good for the clutch and some internal parts on a motorcycle but will typically re- sult in some reduction in power, the opposite of many online claims. Some people say that is okay since they want longevity over power but in practical use, it does seem to have an opposite effect. According to Alexander Smith, son of the legendary Mal- colm Smith and general manager of Malcolm Smith Motorsports, "When we have a motor failure with one of the bikes in our service department or customer bikes on our regular Baja rides, 90 percent of the time they are using Rotella." Rotella does not meet the manufacturer guidelines for motorcycles (so you could have warranty issues if you have VOLUME 57 ISSUE 19 MAY 12, 2020 P77 Shell Rotella has a bit of a cult following, especially among off-road motorcycle riders. It is designed for diesel engines and does NOT meet the recommended oil specifications from the motorcycle manufactures. X